Extension-table-top lock.



D. F. DYKE.

EXTENSION TABLE TOP LOCK.

APPLICATION HLED APR. 7. I915.

2 SHEETS-SHEET I.

5 2 n p A d 6 TU n 6 t nu P Patented Apr. 25, 1916.

D. F. DYKE.

EXTENSION TABLE TOP LOCK.

APPLICATION FILED APR 7 l9l5 Fig 0 WASHINGTON. l7. Cs

a rarer or r ren DARRELL FRANK DYKE, OF CHICAGO, ILLINOIS, ASSIGNOR TOTHE SENG COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

EXTENSION-TABLE-TOIP LOCK.

Specification of Letters Patent.

Patented Apr. 25, 1916..

Application filed April 7, 1915. Serial No. 19,698.

To all whom it may concern Be it known that I, DARRELL FRAnK DYKE, acitizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented new and useful Improvements inExtension-Table-Top Locks, of which the following is a specification,reference being had to the accompanying drawings, forming a partthereof.

The purpose of this invention is to provide an improved device forclosing up and locking the members of the top of an extension table.

It consists in the elements and features of construction shown anddescribed in the drawings as indicated in the claims.

In the drawings :--Figure 1 is a top plan view of a portion of anextension table equipped with this invention. Fig. 2 is a longitudinalvertical section of a portion of such table showing the featuresconstituting the locking device in side elevation at the closed positionof the table top, but with the locking devices disengaged for permittingthe top to be extended. Fig. 3 is a view similar to Fig. 2 showing thetable top extended with fillers intervening between the two top members,and the looking device in looking position. Fig. 4 is a view similar toFig. 3 showing the parts of the locking device at the position occupiedwhen they have been operated for unlocking and forcing apart the topmembers to disengage the tenons.

The drawings show the customary parts of an extension table of customaryconstruction comprising a pedestal or supporting member, A, of which theupper part only is shown, and two top members, B, B connected togetherand mounted upon the supporting member by the usual extension slides, C.Upon the cap or bridging, A of the supporting member, A, there ismounted a notched bar, D, extending longitudinally of the table andhaving its notched edge uppermost, said bar being thus supported uponthe bridging by two angle brackets, E, E, each of which has its verticalflange provided with a longitudinal slot, 6, by means of which thenotched bar is secured to the bracket by the headed studs, E E extendingthrough the slots engaging the bar to permit the bar to slidelongitudinally on the bridging the distance of the length of the slot,6. A coiled spring, F,

is connected at one end to the notched bar, D, and at the other end toone of the brackets,

E, the connection being such as to cause the spring to be stretched bylongitudinal movement of the bar in one direction and to retract the barin the opposite direction and hold it when thus retracted with thestuds, E E stopping its movement in that direction at the end of theslot, 6. Upon one table top member, B, under the outer end portion thereis fulcrumed on a bracket, Gr, a hand lever, H, to which there isconnected a draw bar, J, which extends under the table top and over thebridging alongside the notched bar, and has its inner end provided witha laterally projecting stud, J positioned for engaging the notches ofsaid notched bar. The notches on said bar are straight-shouldered, thatis to say, they are bounded on both sides by vertical edges so as to beadapted for engagement of the abutment, J with them positively, formoving the notched bar positively in either direction by the thrust orpull of the draw bar, but preferably the tops of the teeth interveningbetween the notches are beveled off toward the operating handle lever,H, that is, in the direction to permit the abutment, J to slide up overthem in the inthrust of the draw bar, J, and ride down on them in theopposite direction for certainty of engagement with the inwardly facingshoulders of the notches. Preferably. the rack bar, D, is mounted so asto extend in both directions from the middle point of the supportingmember of the table, 71. 6. so as to extend under both the top memberswhen the table top is closed; and the draw bar, J, similarly extendsunder both top members when the table is closed up, that is, it extendspast their meeting edges. To the underside of the top member, B, uponwhich the operating handle is fulcrumed, near the meeting edges of thetwo top members, there is mounted a hanger or bracket, K, alongside ofwhich the draw bar J, extends, and said hanger has a slot, K which formsa track for the engagement of a stud, J which projects laterally fromthe draw bar to enter said slot which forms a guide track for the samein the longitudinal movement of the draw bar. This slot or track slopesdown ward from both ends toward an intermedi-, ate point, the longerslope being at the end toward the operating handle, the other slopebeing comparatively short and steeper. The purpose of this longer slopeis to accommodate the movement of the end of the draw bar which isconnected to the operating hand lever, H, in view of the fact that thathand lever in its outward movement for closing with the hanger, K, ifthe level of the pivot stud could not change somewhat correspondingly tothe change of level of the pivoted end of the draw bar. By sloping thetrack, K as described and shown, the upward movement of the .pivoted endof the draw bar in the drawing and locking movements of the hand leveris accommodated without forcing downward the inner end of the draw barwith the notched bar or unduly springingor, straining the draw'bar.

Itwill be seen that in operating the device for closing together the topmembers, either with or without intervening fillers, (the length of thenotched bar and of the draw bar being such as to permit them tocooperate for closing up the table, either without fillers as shown inFig. 2, or with as many fillers as would equal by their total widthtwice the length of the-notched bar, in view of the means hereinafterdescribed for causing each top member to move the opposite top memberequally in the opposite direction), the drawing or clamping actioneffected by'means of the engagement of the draw bar with the notched barmay be continued after the top members and the intervening fillers areclose togther, by reason of the yielding of the spring, F, permittingthe notched bar to move longitudinallyof the table after the meeting ofthe top members prevents them from any further longitudinal movement,and that the spring will therefore operate to the extent of the tensiongiven it to hold the top members firmly closed together. It will beseen, therefore, that in reversing the action for unlocking andreleasing the members for extension or to remove fillers, the springwill be relaxed in the first movement of the hand lever inward forunlocking; and it is contemplated that in this movement the stud, J onthe draw'bar will travel the whole length of the longer" downward slopeof the track, K in thebracket, K, and will stand at the lowest point inthat track when the reaction of the spring is complete and the notchedbar is fully retracted to the position shown in Fig. 2, At this stagethe top members with their intervening fillers will be still closedtogether but not pressed together by the tension of the spring. In viewof the engagement of the top members with each other or with theintervening fillers by means of tenons and sockets, which sometimesengage quite tightly making it difiicult to separate them either forextending the tops or removing the fillers, it is desirable to providemeans for pushing the members apart at this stage; and it is for thatpurpose that the inner shoulders as well as the outer shoulders of thenotches of the notched bar are made abrupt, that is, so as to effectpositive engagement of the stud, J on the draw bar, J, therewith; and atthe stage described in the opening movement, that is, when the springhas fully reacted and the stud, J is at the lowest point of the track,K, of the bracket, K, the operator by pushing the hand lever, H, inwardwill positively force outward the top member upon which the hand leveris mounted, Withdrawing it from the opposite top member or from the nextintervening filler, disengaging the tenons and sockets of the top parts.

So far as above described, the movement of the parts both in opening andclosing, locking andunlocking, would be only the movement of the topmember, B, with respect to the supporting member, and the descriptionhas assumed that the opposite top member, B was in any suitable mannerheld in its position either at closed position or at any desiredextended position for the operation of the fillers. But in order thatthe closing and locking devices described may 0perate perfectly forthepurpose of closing up the top, either with or without interveningfillers, that is, without separate manipulation or securement of theopposite top member, the two top members are connected together by meansof racks, M, M, (one at each side) on one top member, and similar racks,M M (one at each side) upon the opposite top member, the two racks ateither side, one on each table top member being engaged by oppositesides of a pinion, N, N, mounted upon the bridging at the top of thesupporting member. By this means all the movement given to the topmember, B, upon which the operating devices described are mounted, iscommunicated directly and equally in opposite direction to the oppositetop member, so that when drawing the member, B, toward the center, themember, B is also drawn toward the center an equal amount; and inwithdrawing the member, B, away from the center for inserting fillers,the member, B is withdrawn in the opposite direction an equal distance;and the locking of the member, B, at closed position as described,serves to lock the member, B, at similar position.

I claim 1. In an extension table comprising a supporting member and topmembers movable thereon for extension, in combination with suchsupporting member and top members, a bar mounted on the supportingmember extended in the direction of movement of the top members andprovided with a series of notches; a draw bar carried with one of thetop members, and a support by which it is mounted for being so carriedand for movement relatively to said top members longitudinally of thetable; means carried by said top member for so moving said draw bar, thenotches of the notched bar being adapted for positive engagement of thedraw bar for thrust of the latter in both longitudinal directions, andthe draw-barsupporting-and-moving means being constructed for causingthe draw bar to be lifted out of engagement with the notched bar at apredetermined limit of inthrust movement of the draw bar.

2. In an extension table comprising a supporting member and top membersmovable thereon for extension, in combination with such supportingmember and top members, a bar mounted on the supporting member extendedin the direction of movement of the top members and having a series ofnotches; a draw bar carried with one of the top members, and a supportby means of which it is mounted for being so carried and for movementrelatively to said top members longitudinally of the table; meanscarried by said top member for so moving said draw bar, the notches ofthe notched bar being adapted for positive engagement of the draw barfor thrust of the latter in both longitudinal directions, the support ofthe draw baron said top member beingacam track along which the fulcrumof the draw bar is moved longitudinally of the table in the thrustingmovement of the draw bar in either direction, said cam track having atthe inner end an up-slope by which the draw bar is lifted out ofengagement with the notched bar after a predetermined point in saidinthrusting movement.

3. In an extension table comprising a supporting member and top membersmovable thereon for extension, in combination with such supportingmember and top members, means for equalizing the movement of said topmembers in opposite directions, causing equal extension of the table inboth directions, a notched bar mounted on the supporting member, a drawbar carried by one of the top members and engaging said notched bar, andmeans by which it is moved longitudinally of said top member while thusengaged with the notched bar, the notches of the notched bar beingadapted for positive engagement of the draw bar by thrust of the latterin either longitudinal direction.

4. In an extension table comprising a supporting member and top membersmovable thereon for extension, in combination with such supportingmember and top members, means mounted on the supporting member and topmembers respectively for causing movement of either top member to movethe other top member equally in the opposite direction, a notched barmounted upon the supporting member having its notched length as great asthe maximum extending movement of either top member, a draw bar mountedon one top member and means for moving it relatively theretolongitudinally of the notched bar, the notches of said notched bar beingadapted for positiveengagement of the draw bar therewith in the thrustof the draw bar inward, and means for withdrawing the draw bar from saidnotches at the limit of the inward thrusting movement of the draw bar.

5. In an extension table comprising a supporting member and top membersmovable thereon for extension, means mounted on the top members andsupporting member respectively for causing the movement of either topmember to move the opposite top member equally in the oppositedirection, a notched bar mounted on the supporting member, a draw barguided by one of the topmembers and adapted for engagement wlth thenotched bar, said notched bar being mounted on the supporting member forlongitudinal movement relatively thereto, and a spring for yieldinglyresisting such movement in the direction of pull of the draw bar, thenotches of said notched bar being adapted for positive engagement of thedraw bar therewith in the thrust of the draw bar in both longitudinaldirections, and means for causing the draw bar to be lifted out ofengagement with the notched bar by the inward thrusting movement of thedraw bar in the closing portion thereof.

In testimony whereof I have hereunto set my hand at Chicago, Illinois,this 3d day of April, 1915.

DARRELL FRANK DYKE.

Witnesses:

FRANK J. SENG, JOHN M. BROST.

Copies of thin patent may be obtained for five cents each, by addressingthe Commissioner oi JPatenta, Washington, D. O.

